I took the general GRE recently, but was apparently too rushed to bother reading the instructions (skipped through them to get through the test quickly to catch a ride back to campus for class). I didn't realize there was an onscreen calculator to make use of (I guess I was doing well enough on the quantitative practice tests--having failed to read the instructions in those instances too--that I assumed there was no calculator allowed, otherwise it would be a bit too easy). I still did well enough on the actual test (165). Nonetheless, very frustrated with myself, as I am assuming I could have boosted my score at least a couple of points considering time spent on some lengthy calculations this round; though maybe I'm mistaken about how much that calculator actually helps... Of course, very foolish of me not to more carefully read the directions. Live and learn.

However, is it worth pointing out in applications that I went through the test without a calculator? Would graduate admissions committees even believe me? Or is the score good enough, even at top programs, not to worry about (for reference, GPA is excellent, PGRE is 870/81%).

Congrats on an excellent GRE score. A 165 on the Q is indistinguishable from any higher score and I am very confident that your admission decisions will not change if you have a 165, 167, or 170. There's no need to worry about this metric.

Therefore, do not mention this calculator issue at all. By the way, the old GRE didn't have such a calculator and many admission committee members don't really keep up to date on what the GRE actually contains so it will just sound very weird.

Finally, the on-screen calculator appears to be very clunky and if you could score 165 without it, I am sure that it would have only slowed you down.